Tests whether sugar in the diet affects blood sugar problems in cystic fibrosis
Compares a low-sugar, high-fat diet with a standard cystic fibrosis diet in adults.
Plain-language title generated from the registry record
Registry title: FEED-Cystic Fibrosis (FEED-CF)
Key facts
- Where
- Atlanta, United StatesSee the site
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults with cystic fibrosis who eat a lot of added sugar. They will get all their food for 8 weeks, either a low-added sugar diet or a standard CF diet.
- Age
- 18 years and older
- Sex
- All sexes can join.
- Disease stage
- Confirmed cystic fibrosis. People with a diagnosis of cystic fibrosis-related diabetes (CFRD) cannot join.
- Earlier treatment
- No change in medical regimen (including medicines and lung flare-ups) in the 21 days before the study visit. No start of a CFTR modulator in the previous 8 weeks.
- Biomarker or test result
- Estimated daily added sugar intake of more than 16 tsp on the Dietary Screener Questionnaire (DSQ). Fasting blood sugar below 126 mg/dL (7 mmol/L) on the screening glucose test.
Main reasons for not taking part
- Confirmed cystic fibrosis-related diabetes (CFRD)
- Night-time tube feeds
- BMI below 18.5 kg/m2
- Long-term steroid use
- Current pregnancy or breastfeeding
Read by machine on 9 November 2026.
Where in United States
- Emory University HospitalAtlanta, United StatesTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Emory University
- Trial code
- NCT05766774
- Record updated
- 3 June 2026
- Original description
The goal of this study is to determine the extent to which excess dietary sugars serve as a precipitating factor in glucose intolerance in adults with cystic fibrosis (CF), a population at especially high risk for a unique form of diabetes (CF-related diabetes, CFRD) and with standard-of-care dietary recommendations (high-calorie, high-fat) that conflict with recommendations for other forms of diabetes.Read full original descriptionShow less
Feeding Study to Optimize Endocrine Dysfunction in Cystic Fibrosis
The goal of this study is to determine the extent to which excess dietary sugars serve as a precipitating factor in glucose intolerance in adults with cystic fibrosis (CF), a population at especially high risk for a unique form of diabetes (CF-related diabetes, CFRD) and with standard-of-care dietary recommendations (high-calorie, high-fat) that conflict with recommendations for other forms of diabetes.
This trial will investigate if the typical high-sugar, high-fat CF diet plays a role in diabetes risk and visceral fat accumulation in people with CF. A total of 30 participants will get a low-added sugar, high-fat diet and the other 30 will get a standard CF diet with no sugar restrictions. Participants will be randomized to the diet group they are assigned. All foods will be provided for 8 weeks.
Inclusion: Confirmed CF diagnosis; Ages 18 years and older; Baseline estimated daily total added sugar intake >16 tsp, as estimated from the Dietary Screener Questionnaire (DSQ).
Exclusion: Chronic steroid use; Clinically instability, defined as no changes in medical regimen (including medications and pulmonary exacerbations) for at least 21 days prior to study visit; Initiation of CFTR modulator within previous 8 weeks OR unstable changes in weight and lung function due to CFTR modulator use; Uncontrolled exocrine pancreatic insufficiency/malabsorption; Any food allergies or intolerances that cannot be accommodated; Any medical condition deemed by the a study physician or PI that may preclude completion of the study or interfere with primary end points; Screening OGTT showing fasting hyperglycemia (≥126 mg/dL); Nocturnal tube feeds; BMI <18.5 kg/m2; Life expectancy < 12 months; Confirmed diagnosis of CFRD; Current pregnancy or lactation; Inability/unwillingness to consume the majority of foods on the menu during the study period; MRI-incompatible metal that cannot be removed for testing; Actively trying to gain or lose weight.